| Key Terms |
Definition |
| API Gravity |
An arbitrary scale expressing the gravity or density of liquid petroleum products.
The measuring scale is calibrated in terms of degrees API; it is calculated as follows:
Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5
The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API
and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below.
Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity.
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| Crude Oil |
A mixture of hydrocarbons that exists in liquid phase in natural underground
reservoirs and remains liquid at atmospheric pressure after passing through
surface separating facilities. Depending upon the characteristics of the crude
stream, it may also include:
Small amounts of hydrocarbons that exist in gaseous phase in natural
underground reservoirs but are liquid at atmospheric pressure after being
recovered from oil well (casinghead) gas in lease separators and are subsequently
commingled with the crude stream without being separately measured. Lease
condensate recovered as a liquid from natural gas wells in lease or field
separation facilities and later mixed into the crude stream is also included;
Small amounts of nonhydrocarbons produced with the oil, such as sulfur and
various metals;
Drip gases, and liquid hydrocarbons produced from tar sands, oil sands,
gilsonite, and oil shale.
Liquids produced at natural gas processing plants are excluded. Crude oil is refined to produce
a wide array of petroleum products, including heating oils; gasoline, diesel and jet fuels;
lubricants; asphalt; ethane, propane, and butane; and many other products used for their
energy or chemical content.
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| Crude Oil Qualities |
Refers to two properties of crude oil, the sulfur content and API gravity, which affect
processing complexity and product characteristics.
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| Petroleum Administration for Defense (PAD) Districts |
Geographic aggregations of the 50 States and the District of Columbia into five districts
by the Petroleum Administration for Defense in 1950. These districts were originally defined
during World War II for purposes of administering oil allocation.
Description and maps of PAD Districts and Refining Districts.
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| Refinery |
An installation that manufactures finished petroleum products from crude oil, unfinished oils,
natural gas liquids, other hydrocarbons, and oxygenates.
|
| Refinery Input, Total |
The raw materials and intermediate materials processed at refineries to produce finished petroleum
products. They include crude oil, products of natural gas processing plants, unfinished oils,
other hydrocarbons and oxygenates, motor gasoline and aviation gasoline blending components
and finished petroleum products.
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| Sulfur |
A yellowish nonmetallic element, sometimes known as "brimstone." It is present at various
levels of concentration in many fossil fuels.
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Definitions